Ecommerce in another country from sellers and buyers

[Whippino]

Hello, 

I am based in UK, and I've been asked to run an ecommerce shop in Italy.

The seller has his physical shop in Italy and the buyers will be only in Italy, no international shipping.

Basically I will get only a commission per product sold on the website.

How does it work taxwise, can I open my ltd in uk or I will need to open a company in Italy?

How about the taxes? I will obviously sell for 100 and give back 90 to the seller if my commision is 10% for instance. what should it be the correct pipeline?

help please